Merge pull request #282 from xamarin/pr-abock-slightly-better-gtk

GtkNSViewHost: replace the native GtkNSView with a managed one

2 files changed, 393 insertions, 12 deletions

diff --git a/main/src/addins/MonoDevelop.TextEditor/MonoDevelop.TextEditor.Cocoa/CocoaTextViewContent.cs b/main/src/addins/MonoDevelop.TextEditor/MonoDevelop.TextEditor.Cocoa/CocoaTextViewContent.cs
index a3d3b632c5..d1c4af7971 100644
--- a/main/src/addins/MonoDevelop.TextEditor/MonoDevelop.TextEditor.Cocoa/CocoaTextViewContent.cs
+++ b/main/src/addins/MonoDevelop.TextEditor/MonoDevelop.TextEditor.Cocoa/CocoaTextViewContent.cs
@@ -31,11 +31,10 @@ using Microsoft.VisualStudio.Text.Editor;
 using Microsoft.VisualStudio.Utilities;
 
 using MonoDevelop.Components;
-using MonoDevelop.Components.Commands;
 using MonoDevelop.Core;
+using MonoDevelop.Core.FeatureConfiguration;
 using MonoDevelop.Ide.Commands;
 using MonoDevelop.Projects;
-using Microsoft.VisualStudio.Text.Editor.Implementation;
 
 namespace MonoDevelop.TextEditor
 {
@@ -73,20 +72,47 @@ namespace MonoDevelop.TextEditor
 	{
 		ICocoaTextViewHost textViewHost;
 		NSView textViewHostControl;
-		EmbeddedNSViewControl embeddedControl;
+		GtkNSViewHostControl embeddedControl;
 
-		sealed class EmbeddedNSViewControl : Control
+		static readonly Lazy<bool> useManagedGtkNSViewHost = new Lazy<bool> (
+			() => FeatureSwitchService.IsFeatureEnabled ("ManagedGtkNSViewHost").GetValueOrDefault ());
+
+		abstract class GtkNSViewHostControl : Control
+		{
+			public Gtk.Widget GtkView { get; protected set; }
+		}
+
+		sealed class ManagedGtkNSViewHostControl : GtkNSViewHostControl
+		{
+			public ManagedGtkNSViewHostControl (ICocoaTextViewHost textViewHost)
+			{
+				if (textViewHost == null)
+					throw new ArgumentNullException (nameof (textViewHost));
+
+				GtkView = new Gtk.GtkNSViewHost (textViewHost.HostControl);
+				GtkView.Show ();
+			}
+
+			protected override object CreateNativeWidget<T> ()
+				=> GtkView;
+
+			public override bool HasFocus
+				=> GtkView.HasFocus;
+
+			public override void GrabFocus ()
+				=> GtkView.GrabFocus ();
+		}
+
+		sealed class LegacyGtkNSViewHostControl : GtkNSViewHostControl
 		{
 			readonly ICocoaTextViewHost textViewHost;
 			readonly NSView nsView;
 
 			bool nativeViewNeedsFocus;
 
-			public Gtk.Widget GtkView { get; }
-
 			public bool IsGrabbingFocus { get; private set; }
 
-			public EmbeddedNSViewControl (ICocoaTextViewHost textViewHost)
+			public LegacyGtkNSViewHostControl (ICocoaTextViewHost textViewHost)
 			{
 				this.textViewHost = textViewHost ?? throw new ArgumentNullException (nameof (textViewHost));
 				this.nsView = textViewHost.HostControl;
@@ -164,11 +190,18 @@ namespace MonoDevelop.TextEditor
 			textViewHost = Imports.TextEditorFactoryService.CreateTextViewHost (TextView, setFocus: true);
 			textViewHostControl = textViewHost.HostControl;
 
-			embeddedControl = new EmbeddedNSViewControl (textViewHost);
-			TextView.GotAggregateFocus += (sender, e) => {
-				if (!embeddedControl.IsGrabbingFocus)
-					embeddedControl.GtkView.GrabFocus ();
-			};
+			if (useManagedGtkNSViewHost.Value) {
+				embeddedControl = new ManagedGtkNSViewHostControl (textViewHost);
+			} else {
+				var legacyEmbeddedControl = new LegacyGtkNSViewHostControl (textViewHost);
+				embeddedControl = legacyEmbeddedControl;
+
+				TextView.GotAggregateFocus += (sender, e) => {
+					if (!legacyEmbeddedControl.IsGrabbingFocus)
+						embeddedControl.GtkView.GrabFocus ();
+				};
+			}
+
 			TextView.Properties.AddProperty (typeof (Gtk.Widget), embeddedControl.GtkView);
 
 			return embeddedControl;
diff --git a/main/src/addins/MonoDevelop.TextEditor/MonoDevelop.TextEditor.Cocoa/GtkNSViewHost.cs b/main/src/addins/MonoDevelop.TextEditor/MonoDevelop.TextEditor.Cocoa/GtkNSViewHost.cs
new file mode 100644
index 0000000000..edc46e22e7
--- /dev/null
+++ b/main/src/addins/MonoDevelop.TextEditor/MonoDevelop.TextEditor.Cocoa/GtkNSViewHost.cs
@@ -0,0 +1,348 @@
+//
+// Copyright (c) Microsoft Corp. (https://www.microsoft.com)
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+using System;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+using AppKit;
+using CoreGraphics;
+using ObjCRuntime;
+
+namespace Gtk
+{
+	sealed class GtkNSViewHost : Widget
+	{
+		const string LIBGTKQUARTZ = "libgtk-quartz-2.0.dylib";
+
+		[DllImport (LIBGTKQUARTZ)]
+		static extern IntPtr gdk_quartz_window_get_nsview (IntPtr window);
+
+		[DllImport (LIBGTKQUARTZ)]
+		static extern IntPtr gdk_quartz_event_get_nsevent (IntPtr evnt);
+
+		[DllImport (LIBGTKQUARTZ)]
+		static extern void gdk_window_coords_to_parent (
+			IntPtr window,
+			double x,
+			double y,
+			out double parent_x,
+			out double parent_y);
+
+		[DllImport (LIBGTKQUARTZ)]
+		static extern bool gdk_window_has_native (IntPtr window);
+
+		static NSEvent GetNSEvent (Gdk.Event evnt)
+		{
+			if (evnt == null || evnt.Handle == IntPtr.Zero)
+				return null;
+
+			var nsEventHandle = gdk_quartz_event_get_nsevent (evnt.Handle);
+			if (nsEventHandle == IntPtr.Zero)
+				return null;
+
+			return Runtime.GetNSObject<NSEvent> (nsEventHandle);
+		}
+
+		NSView view;
+		NSView superview;
+
+		public GtkNSViewHost (NSView view)
+		{
+			this.view = view ?? throw new ArgumentNullException (nameof (view));
+
+			WidgetFlags |= WidgetFlags.NoWindow;
+		}
+
+		void UpdateViewFrame ()
+		{
+			LogEnter ();
+			try {
+				if (view == null)
+					return;
+
+				var window = GdkWindow;
+				var allocation = Allocation;
+				double x = allocation.X;
+				double y = allocation.Y;
+
+				while (window != null && !gdk_window_has_native (window.Handle)) {
+					gdk_window_coords_to_parent (window.Handle, x, y, out var nx, out var ny);
+					Log ($"({x},{y}) -> ({nx},{ny})");
+					x = nx;
+					y = ny;
+					window = window.Parent;
+				}
+
+				view.Frame = new CGRect (x, y, allocation.Width, allocation.Height);
+				Log ($"Frame: {view.Frame}");
+			} finally {
+				LogExit ();
+			}
+		}
+
+		static NSView RecursivelyFindSubviewForPredicate (NSView view, Predicate<NSView> predicate)
+		{
+			if (predicate (view))
+				return view;
+
+			var subviews = view.Subviews;
+			if (subviews != null && subviews.Length > 0) {
+				foreach (var subview in subviews) {
+					if (subview != null) {
+						var foundView = RecursivelyFindSubviewForPredicate (subview, predicate);
+						if (foundView != null)
+							return foundView;
+					}
+				}
+			}
+
+			return null;
+		}
+
+		NSView GetAcceptsFirstResponderView ()
+			=> RecursivelyFindSubviewForPredicate (view, v => v.AcceptsFirstResponder ());
+
+		protected override void OnDestroyed ()
+		{
+			LogEnter ();
+
+			view?.RemoveFromSuperview ();
+			view = null;
+			superview = null;
+
+			base.OnDestroyed ();
+
+			LogExit ();
+		}
+
+		protected override void OnRealized ()
+		{
+			LogEnter ();
+
+			GdkWindow = Parent.GdkWindow;
+
+			if (GdkWindow != null && GdkWindow.Handle != IntPtr.Zero) {
+				var superviewHandle = gdk_quartz_window_get_nsview (GdkWindow.Handle);
+				if (superviewHandle != IntPtr.Zero)
+					superview = Runtime.GetNSObject<NSView> (superviewHandle);
+			}
+
+			if (superview != null && view != null) {
+				view.Hidden = true;
+				superview.AddSubview (view);
+				UpdateViewFrame ();
+
+				CanFocus = GetAcceptsFirstResponderView () != null;
+			}
+
+			base.OnRealized ();
+
+			LogExit ();
+		}
+
+		protected override void OnUnrealized ()
+		{
+			LogEnter ();
+
+			if (IsMapped)
+				Unmap ();
+
+			view?.RemoveFromSuperview ();
+			superview = null;
+
+			base.OnUnrealized ();
+			LogExit ();
+		}
+
+		protected override void OnMapped ()
+		{
+			LogEnter ();
+
+			view.Hidden = false;
+
+			base.OnMapped ();
+
+			if (IsMapped)
+				UpdateViewFrame ();
+
+			LogExit ();
+		}
+
+		protected override void OnUnmapped ()
+		{
+			LogEnter ();
+
+			view.Hidden = true;
+
+			base.OnUnmapped ();
+
+			LogExit ();
+		}
+
+		protected override bool OnConfigureEvent (Gdk.EventConfigure evnt)
+		{
+			LogEnter ();
+			try {
+				return base.OnConfigureEvent (evnt);
+			} finally {
+				LogExit ();
+			}
+		}
+
+		protected override void OnSizeRequested (ref Requisition requisition)
+		{
+			LogEnter ();
+			try {
+				if (view == null) {
+					Log ("Calling base. 'view' is null");
+					base.OnSizeRequested (ref requisition);
+					return;
+				}
+
+				var fittingSize = view.FittingSize;
+				requisition.Width = (int)fittingSize.Width;
+				requisition.Height = (int)fittingSize.Height;
+				Log ($"Setting requisition to {requisition.Width}x{requisition.Height}");
+			} finally {
+				LogExit ();
+			}
+		}
+
+		protected override void OnSizeAllocated (Gdk.Rectangle allocation)
+		{
+			LogEnter ();
+
+			base.OnSizeAllocated (allocation);
+
+			UpdateViewFrame ();
+
+			LogExit ();
+		}
+
+		protected override bool OnFocusInEvent (Gdk.EventFocus evnt)
+		{
+			LogEnter ();
+			try {
+				var acceptsFirstResponderView = GetAcceptsFirstResponderView ();
+				if (acceptsFirstResponderView?.Window == null)
+					return false;
+
+				acceptsFirstResponderView.Window.MakeFirstResponder (acceptsFirstResponderView);
+
+				return base.OnFocusInEvent (evnt);
+			} finally {
+				LogExit ();
+			}
+		}
+
+		protected override bool OnFocusOutEvent (Gdk.EventFocus evnt)
+		{
+			LogEnter ();
+			try {
+				var firstResponder = view?.Window.FirstResponder as NSView;
+				if (firstResponder != null && view?.AncestorSharedWithView (firstResponder) == view)
+					firstResponder.Window.MakeFirstResponder (null);
+				return base.OnFocusOutEvent (evnt);
+			} finally {
+				LogExit ();
+			}
+		}
+
+		bool ForwardEvent<TEvent> (
+			TEvent evnt,
+			Action<NSView, NSEvent> forwardCall,
+			Func<TEvent, bool> baseCall) where TEvent : Gdk.Event
+		{
+			var acceptsFirstResponderView = GetAcceptsFirstResponderView ();
+			if (acceptsFirstResponderView == null)
+				return false;
+
+			var nsEvent = GetNSEvent (evnt);
+			if (nsEvent == null)
+				return false;
+
+			forwardCall (acceptsFirstResponderView, nsEvent);
+
+			return baseCall (evnt);
+		}
+
+		protected override bool OnKeyPressEvent (Gdk.EventKey evnt)
+		{
+			LogEnter ();
+			try {
+				return ForwardEvent (
+					evnt,
+					(v, e) => v.KeyDown (e),
+					base.OnKeyReleaseEvent);
+			} finally {
+				LogExit ();
+			}
+		}
+
+		protected override bool OnKeyReleaseEvent (Gdk.EventKey evnt)
+		{
+			LogEnter ();
+			try {
+				return ForwardEvent (
+					evnt,
+					(v, e) => v.KeyUp (e),
+					base.OnKeyReleaseEvent);
+			} finally {
+				LogExit ();
+			}
+		}
+
+		#region Tracing
+
+		int traceDepth = 0;
+
+		[Conditional ("DEBUG")]
+		void LogIndent ()
+			=> Debug.Write (new string (' ', traceDepth * 2));
+
+		[Conditional ("DEBUG")]
+		void Log (string message, [CallerMemberName] string memberName = null)
+		{
+			LogIndent ();
+			Debug.WriteLine ($"{memberName}: {message}");
+		}
+
+		[Conditional ("DEBUG")]
+		void LogEnter ([CallerMemberName] string memberName = null)
+		{
+			LogIndent ();
+			Debug.WriteLine ($"Enter: {memberName}");
+			traceDepth++;
+		}
+
+		[Conditional ("DEBUG")]
+		void LogExit ([CallerMemberName] string memberName = null)
+		{
+			traceDepth--;
+			LogIndent ();
+			Debug.WriteLine ($"Exit: {memberName}");
+		}
+
+		#endregion
+	}
+}
\ No newline at end of file